The question is rather hard and my opinion will very possibly change with more pictures or when I get the figs to my hands, but I ended up voting Bifur for that beautiful hair piece with beard, even if it's quite useless outside of the context, considering the axe head. Dwalin is high in my books, and so is Gloin and Balin. Fili isn't bad either. I may need the movie to convince me about Nori's hairstyle, otherwise the fig is quite cool. I don't know why but Bofur's torso seems to me a bit unpolished compared to the others, as if the printing didn't work properly.

I had to vote Balin. His hair/beard piece is great and overall he is one of the best LEGO representations of the characters. I also really like Dori, and Thorin is up there as well, but not only is Balin's figure really excellent, but he is also my favourite of the dwarves.

"One Ring to rule them all, One Ring to find them, One Ring to bring them all, and in the darkness bind them!"

Already got the names committed to memory. Fairly easy as they mostly rhyme. I think Tolkien designed it that way so children would find it easy to remember so many different characters.

Maybe.. but most of the dwarves are only mentioned once or twice through the entire Hobbit book. Tolkien could of just as easily named off 4 or 5 of the dwarves and left the rest as no named grunts. Also in the book most of them don't even carry any weapons besides small knives until the final battle, and most have absolutely no distinguishing features besides their cloak color. For this reason I think Jackon is going to take a LOT of liberties with The Hobbit, much more so than he did with LotR. It would make sense too considering the Hobbit is much more a children's tale and doesn't have the same amount of detail or plot development LotR does.

I've found that Jackson's portrayal of the dwarves has helped me memorize all the names. Since his versions are all so unique from each other, it is easier to tell the difference. Also, the fact that we now have a visual reference to go by helps. I could see a picture of any of the dwarves and instantly know who it is. I think the films are going to make the dwarves much more memorable characters than they were in the book.

"One Ring to rule them all, One Ring to find them, One Ring to bring them all, and in the darkness bind them!"

Already got the names committed to memory. Fairly easy as they mostly rhyme. I think Tolkien designed it that way so children would find it easy to remember so many different characters.

Actually Tolkien didn't design the dwarf names, they are taken from Edda, ancient Skandinavian folklore epic.

These figures are lovely in all. I voted for Balin, he's always been my favourite of these characters and TLG did great job on him. I like Fili, Bifur and Bofur (Whose torso is a bit plain as Haltiamieli mentioned, but the hat is awesome anyways) too. Dori's hair/beard piece is fantastic, but I think it (And Ori's hair and Gloin's beard) should be reddish brown instead.

Voted for Fili looks good (his hair and his face and his torso is also nicely printed).
The ugliest in my opinion is Dwalin, I really don't like bald minifigures (Darth Malgus is the only exception), he'll probably get a black hairpiece (if it fits).

EDIT: it's nice how they did Bombur his bald spot, and just didn't print some hair next to the stud on his haid. Dwalin would look better if they used some sort of cap like Darth Maul (or Savage Opress) without the horns.

Voted for Fili looks good (his hair and his face and his torso is also nicely printed).
The ugliest in my opinion is Dwalin, I really don't like bald minifigures (Darth Malgus is the only exception), he'll probably get a black hairpiece (if it fits).

EDIT: it's nice how they did Bombur his bald spot, and just didn't print some hair next to the stud on his haid. Dwalin would look better if they used some sort of cap like Darth Maul (or Savage Opress) without the horns.

I think those caps on the satr wars figures looks bad, the split is too aparent and the stud beoming a hole looks abit odd.

Dwalin is my favorite, and I don't think they needed to use any kind of cap for him. I really don't care for minifigs with "bald caps" - the goblins in the Goblin Town set look terribly macrocephalic IMO, and Darth Maul and his brother have seams that are way too noticeable for me to really like them. I suppose this is all part of the "minifigs creeping into excessive detail" debate - I like minifigs with some detailing, but not super-detailed like action figures - especially when those details ruin what I think of as classic Lego proportions. So I'm just fine with a bald minifig having a stud on the top of his head. It's Lego. Studs are part of the look.

I like Balin, but it's a narrow lead over Oin, Gloin, and Dwalin. Balin's hair/beard look great for use on any number of older dwarves, or wizards/sages/etc.

Oin & Gloin avoided the lead by my slight dislike of their beard coloring; Gloin lacking printed braids makes his big mass of reddish brown rather bland, and Oin's beard & mustache being a different tone entirely from his hair kinda disappoints me, too. Dwalin missed simply because his look, aside from the tattoos, isn't as unique as the others. I can pop the helmet off any of my yellow dwarves and achieve something similar.

That said, Dwalin's lack of hair means his beard is possibly the most versatile of the bunch, as we'll probably be able to throw on various hair & helmet pieces to add another black-beard variety to our dwarves & vikings.